GRAS 46DD 1/8'' CCP Pressure Standard Microphone Set
Freq range: 6.5 Hz to 140 kHz
Dyn range: 52 dB(A) to 174 dB
Sensitivity: 0.8 mV/Pa
GRAS 46DD 1/8'' CCP Pressure Microphone Set
Technology
Introduction
Through a close cooperation with our customers, we know that data-safety is highly important because the costs related to unsuited and unreliable sensors may determine whether your project turns into a success or not.
For our users, data safety translates directly into requests for easier microphone selection, simple system configuration and reduction of measurement errors.
To meet these requirements, we invented the microphone set concept. It is simple, reliable and robust and consists of a microphone cartridge and preamplifier combination, which is calibrated as one unit. This eliminates errors because there is only one sensitivity value to account for and the risk of contaminating the interface is eliminated. Combine this with our unique and proven design and you have the most reliable measurement microphone sets available in the industry today.
Typical application and use
The 46DD is a pressure microphone set and as such optimized for acoustic measurements of the sound source in a closed coupler or the measurement of sound pressure at a boundary or wall; in which case the microphone forms part of the wall and measures the sound pressure on the wall itself.
Regarding temperature range, see the Specifications. Should higher temperature limits be required, we recommend considering the GRAS probe microphones where the microphone and preamplifier can be isolated from the hot source.
Design
The GRAS 46DD is a high-performance standard microphone set. In our clean-room environment the set is assembled and sealed with a label. However, the microphone set can be dismounted, if you wish to use the components separately.
Microphone
The microphone cartridge is the high-quality GRAS 40DD 1/8" Prepolarized Pressure Microphone, designed for long-term reliability in multiple environments.
Preamplifier
The preamplifier is the GRAS 26CB Preamplifier which is inclusive TEDS and based on our well-known circuit board substrates. In the industry these are famous for their low self-noise, wide frequency and excellent slew rate performance.
Compatibility
To perform as specified the GRAS 46DD microphone set requires a constant current input module that can deliver 4 mA and 24 V unloaded CCP voltage supply. If the constant current supply is lower, the capability of driving long cables is reduced and consequently the upper frequency is reduced. If the voltage supply is lower it will influence the upper dynamic range.
The microphone set is terminated with a Microdot connector. Ready to use coax cable assemblies of various types and lengths are available in standard as well as customized lengths.
The 46DD is IEEE 1451.4 TEDS 27v. 1.0 compliant. If your measurement platform supports Transducer Electronic Data Sheets you will be able to read and write data like properties and calibration data.
System verification
The functionality of TEDS is very useful to determine which microphone is connected to which input channel. However, it is not a check of whether the microphone is within specifications or not. For daily verification and check of your measurement setup, we therefore recommend using a sound source like the GRAS 42AG Sound Calibrator.
For proper sensitivity calibration we recommend using a reference sound source like the GRAS 42AP Intelligent Pistonphone.
Calibration
When leaving the factory, all GRAS microphones have been calibrated in a controlled laboratory environment using traceable calibration equipment. Depending on the use, measurement environment and internal quality control programs we recommend that the microphone is recalibrated at least once a year.
We offer two kinds of calibration as an optional after-sales service: GRAS Traceable Calibration and GRAS Accredited Calibration.
GRAS Traceable Calibration is a traceable calibration performed by trained personnel under controlled conditions according to established procedures and standards. This is identical to the rigorous calibration that all GRAS microphones are subjected to as an integral part of our quality assurance.
GRAS Accredited Calibration is performed by the GRAS Accredited Calibration Laboratory that has been accredited in accordance with ISO 17025 by DANAK, the Danish Accreditation Fund.
If you want a new microphone set delivered with an accredited calibration in stead of the default factory calibration, specify this when ordering.
Learn more at gras/calib.
Quality and warranty
GRAS microphone sets are made of components from our proven standard portfolio and are all manufactured of high-quality material and branded parts that were chosen and processed to ensure life-long stability and robustness.
All parts are manufactured and assembled at the factory in Denmark by skilled and dedicated operators in a verified clean-room environment. The microphone diaphragm, body and unique protection grid are made of high-grade stainless steel and make the microphone set resistant to physical damage as well as corrosion caused by aggressive air or gasses.
This, together with the enforced gold-plated microphone terminal guarantees a highly reliable connection. Thanks to the high quality, our warranty against defective materials and workmanship is 5 years.
Service
Should you by mistake damage the diaphragm on a GRAS microphone we will in most cases be able to exchange it at a very reasonable cost and short turn-around time. This not only protects your investment but also meets your quality assurance department since you do not have to worry about new serial numbers etc.
Specifications
Typical frequency response (without protection grid).
GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.
Dimensions
Ordering info
Optional items
GRAS AA0070 |
3 m Microdot - BNC Cable |
GRAS AL0029 |
1/4" Microphone Holder, POM |
GRAS AL0013 |
1/4" Microphone Holder, Stainless Steel |
GRAS AL0005 |
Swivel head |
GRAS AL0006 |
Tripod |
GRAS RA0173 |
1/8” Nosecone |
GRAS AM0071 |
Windscreen for 1/4" Microphones |
GRAS 12AL |
1-Channel CCP Power Module with A-weighting filter |
GRAS 12AQ |
2-Channel Universal Power Module with signal conditioning and PC interface |
GRAS 42AG |
Multifunction Sound Calibrator, Class 1 |
GRAS 42AP |
Intelligent Pistonphone, Class 0 |
GRAS CA0029 |
Traceable Calibration of Microphone Set |
GRAS CA2301 |
Accredited Calibration of Microphone Set |
GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.